Duncan, better known in the Masters of the Universe franchise as Man-At-Arms, is the chief technologist and weapons researcher/developer for the Kingdom of Eternia. A close friend and counselor to King Randor & Queen Marlena and a mentor figure to Prince Adam, he is one of only three people (the other two being the Sorceress of Castle Grayskull and Orko) who know Adam's secret dual-identity as He-Man.
He-Man and the Masters of the Universe (1983)
In Filmation's animated series, Man-At-Arms, despite being a soldier and a master of weapons, is primarily peaceful and prefers alternatives to fighting. Though his stature suggests a warrior, his character is primarily patterned after skilled mechanics, and he likes to spend his time working on all the kingdom's vehicles. He is also Teela's foster father (something already mentioned in a couple of pre-Filmation stories), as well as mentor to Prince Adam. The Sorceress of Castle Grayskull asked Man-At-Arms to adopt Teela because she felt she could not raise her daughter & protect Castle Grayskull at the same time and believed that if others knew of Teela's true destiny, it would make her daughter a target.
Man-At-Arms wears armor which is slightly different from that of the standard uniform of the royal guards. His moustache was not present on the original figure, having been added by Filmation to make him look older, wiser and more fatherly - although original prototype sketches for the Man-At-Arms figure gave him a goatee beard. He is often pestered by court jester Orko, as Orko's magic tricks often backfire directly at him.
Along with Adam/He-Man and Teela, Duncan is one of the cartoon series' most central and most often seen characters.
He-Man and the Masters of the Universe (2002)
The 2002 cartoon by Mike Young Productions portrays Duncan as a much more serious character and more of a warrior, with a deeper connection to the Sorceress than was previously shown. As in the original Filmation series, Man-At-Arms is Teela's adoptive father (and is implied to be her biological father as well). Man-At-Arms has a close mentor/student relationship with Adam, in addition to aiding He-Man and leading the Masters (as the Heroic Warriors are called in the 2002 version), and is close friends with Adam's father King Randor. It is also revealed that Fisto, a minor hero character in the 1983 series, is Duncan's brother. Duncan's mentor, Dekker, also appears in the series.
- He-Man and the Masters of the Universe - Season One, Volume One. IGN. Retrieved 2009-10-16.
- The Best of He-Man and the Masters of the Universe : DVD Talk Review of the DVD Video. DVDTalk. Retrieved 2012-11-06.